This invention relates to solvent reclaiming drying tumblers used in the drycleaning industry.
There are presently two major types of solvent employed in drycleaning--perchloroethylene, which is expensive, non-inflammable, and easily recoverable, and petroleum solvent, which is relatively inexpensive, inflammable, and difficult to recover for having a low vapor pressure. Tumblers using petroleum solvent have heretofore generally been exhausted to the atmosphere; however, with both increasing cost for petroleum solvent and concern for air quality, it is desired to condense and reclaim the petroleum solvent evaporated from drycleaned clothes.
Drying tumblers for recovering easily recoverable perchloroethylene are known in the art. An example in U.S. Pat. No. 2,910,783, which shows a solvent reclaiming drying tumbler having an endless duct system including a basket, fan, heater, and condenser in its circuit so that a stream of heated solvent-laden air may be driven through the condenser. The tumbler also has a branch duct allowing bypassing of the condenser during both a preheating cycle, which occurs before, and a deodorizing cycle, which occurs after, a solvent reclaiming cycle wherein the solvent-laden air is passed through the condenser in which the solvent is condensed.